Tony's 300 Whisper Contender Update
Date: Sat, 7 Sep 2002 22:25:04 -0500
I got my reloading dies (from Redding) here and have been playing around with it. I've got to tell you, my accuracy results with subsonic loads have been nothing to brag about, and I'm not sure what the problem is.
Regarding powder.... I tried some IMR-4227 that seemed promising, but the velocity fluctuations were bad. When my chronograph reads 80 ft/sec difference from one shot to the next, something's not right. I switched to Reloader 7 and it made a huge improvement. Suddenly I was getting readings like 980, 979, 979, 981 . . . That's amazingly consistent velocity, I didn't even think it was possible with smokeless powder.
I got some Hornady 180 grain HPBT Natl Match bullets and loaded them to 980 ft/sec, figuring this would give me good accuracy.... Not exactly. I found myself consistently putting four shots into 1 3/4" group, with each group spoiled by a single flyer that went 2" high. I even fired a 10-shot group that put 8 shots into 1 3/4" with two flyers landing together a couple of inches above! That was one morning... The next morning I came back for more experimentation and found myself simply getting 3-inch groups with no real pattern. It's like voodoo or something, I just don't get it.
I know the gun should be able to do better, since I shot a 7/8" group using Cor-Bon supersonic ammo. But the Cor-Bon subsonic ammo didn't do so hot. There must be some trick to making it shoot with subsonic loads.
After carefully inspecting some of the targets, it looks like the bullets may be yawing and striking at a slight sideways angle. I can't think why they would, though. The twist rate is supposed to be enough to stabilize a 240-grain bullet at subsonic velocity, so one would imagine a 180-grain bullet would be even more stable. Maybe it's because my velocity is below standard? Next time I might pump it up to about 1040 ft/sec and see if that helps or hurts. When I worked up the 980 ft/sec load, my theory was that I wanted to keep it definitely below the trans-sonic buffeting. But if I'm sacrificing stability, that might have been the wrong idea.
I shot up all the Hornady bullets I had on hand, and am now waiting for some surplus 180-grain SPBTs to arrive from Midsouth, and also some Magnus 165-grain flat-nosed cast lead bullets, and some of the expensive Sierra 240-grain Match Kings. So, I will have plenty of different projectiles to play around with. I intend to solve this puzzle, but it may just take a while.
By the way.... Denzel Roberts is going to make a nice stock for me. It will take several months, and I might get it around this coming February. Some things can't be rushed, I know, but that's sure going to seem like a long wait for me!
Tony Belding, Hamilton Texas
Tony can be contacted at firstname.lastname@example.org if you would like additional information. I would like to offer a special thanks to Tony for sharing his exceptional Contender!
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